Background: Treatment for chronic low back pain (LBP) includes different forms of exercises, that to date have resulted in only small to moderate treatment effects. To enhance the treatment effects, different classification systems have been developed to classify people with LBP into more homogeneous subgroups leading to specific treatments for each subgroup.
Objective: The purpose of this study was to compare the efficacy of a treatment based on the Movement System Impairment (MSI) model with a treatment consisting of symptom-guided stretching and strengthening exercises in people with chronic LBP.
Design: The study was a 2-arm, prospectively registered, randomized controlled trial with a blinded assessor.
Setting: The study setting was a university physical therapy clinic in Brazil.
Patients: A total of 148 participants with chronic LBP participated in the study.
Interventions: Participants were randomly allocated to an 8-week treatment of either treatment based on the MSI-based classification system or symptom-guided stretching and strengthening exercises.
Measurements: Measures of pain intensity, disability, and global impression of recovery were obtained by a blinded assessor at baseline and at follow-up appointments at 2, 4, and 6 months after randomization.
Results: There were no significant between-group differences for the primary outcomes of pain intensity at 2 months (mean difference = 0.05, 95% CI = 0.90 to 0.80) and disability at 2 months (mean difference = 0.00, 95% CI = 1.55 to 1.56). There also were no statistically significant differences between treatment groups for any of the secondary outcome measures.
Limitations: Participants and physical therapists were not masked.
Conclusions: People with chronic LBP had similar improvements in pain, disability, and global impression of recovery with treatment consisting of symptom-guided stretching and strengthening exercises and treatment based on the MSI model.

Background: Treatment for chronic low back pain (LBP) includes different forms of exercises, that to date have resulted in only small to moderate treatment effects. To enhance the treatment effects, different classification systems have been developed to classify people with LBP into more homogeneous subgroups leading to specific treatments for each subgroup.
Objective: The purpose of this study was to compare the efficacy of a treatment based on the Movement System Impairment (MSI) model with a treatment consisting of symptom-guided stretching and strengthening exercises in people with chronic LBP.
Design: The study was a 2-arm, prospectively registered, randomized controlled trial with a blinded assessor.
Setting: The study setting was a university physical therapy clinic in Brazil.
Patients: A total of 148 participants with chronic LBP participated in the study.
Interventions: Participants were randomly allocated to an 8-week treatment of either treatment based on the MSI-based classification system or symptom-guided stretching and strengthening exercises.
Measurements: Measures of pain intensity, disability, and global impression of recovery were obtained by a blinded assessor at baseline and at follow-up appointments at 2, 4, and 6 months after randomization.
Results: There were no significant between-group differences for the primary outcomes of pain intensity at 2 months (mean difference = 0.05, 95% CI = 0.90 to 0.80) and disability at 2 months (mean difference = 0.00, 95% CI = 1.55 to 1.56). There also were no statistically significant differences between treatment groups for any of the secondary outcome measures.
Limitations: Participants and physical therapists were not masked.
Conclusions: People with chronic LBP had similar improvements in pain, disability, and global impression of recovery with treatment consisting of symptom-guided stretching and strengthening exercises and treatment based on the MSI model.